The present invention relates to a vibration damper, in particular a single-tube shock absorber.
In single-cylinder vibration dampers, which are divided into two working chambers by a piston which is movable back and forth, it is necessary to provide volume compensation, which is required as a result of the uneven displacement of the damper liquid by the piston rod. A volume compensation of this type may be provided by elements and/or compressible media that are situated in a working chamber opposite to the piston rod.
Vibration dampers are known, for example, from DE 197 50 414 C2 and DE 18 63 823.
A vibration damper having a working cylinder and a working piston axially displaceable therein is disclosed in DE 1 195 615. The working piston divides the working cylinder into a first and a second working chamber. Furthermore, the known vibration damper comprises a compensation cylinder having a compensation piston situated so it is axially displaceable therein, so that the compensation cylinder is divided into a first and second working chamber. The first working chamber of the compensation cylinder is filled with liquid and is connected to the second working chamber of the working cylinder via a comparatively narrow throttle channel. A spring, which presses against the sealed compensation piston, is provided in the second working chamber of the compensation cylinder, which is not filled with liquid. In the known vibration damper, the compensation cylinder is rotated by 90° in relation to the working cylinder. The disadvantage in this case is that the compensation cylinder is situated on the front end of the working cylinder, at an especially highly loaded point of the vibration damper, because of which a wall of the compensation cylinder must be implemented as appropriately thick and thus the vibration damper as such has a relatively high weight.
An object of the present invention is to provide an improved vibration damper which addresses the available installation space in the area of the vibration damper that is becoming smaller and smaller.
This object has achieved according to the present invention by providing that the compensation cylinder is at and diagonal to the longitudinal end of the working cylinder.
The present invention is based on the general concept, in a vibration damper according to the species having a working cylinder and a compensation cylinder. In a known way, the vibration damper according to the present invention comprises a working cylinder having a working piston axially displaceable therein, which piston divides the working cylinder into a first and second working chamber, as well as a compensation cylinder having a compensation piston, which divides the compensation cylinder into a first and a second working chamber, and the first working chamber of the compensation cylinder being pressure-connected to the second working chamber of the working cylinder.
It is especially advantageous in regard to the compensation cylinder situated at the longitudinal end of the working cylinder in a diagonal position that an available installation space in the area of a vehicle connection which has small dimensions may be constructively used advantageously in this way. Due to the diagonal configuration of the compensation cylinder, a free space in the form of a hollow channel arises in the connection area of the vibration damper to the suspension, which may be used, for example, for a driveshaft passage.
According to an advantageous refinement of the present invention, the second working chamber of the compensation cylinder is filled with the gas. A gas is a compressible medium that is favorable in comparison to compressible elements known from the prior art, such as elastic materials or springs, and is simultaneously free of wear. Depending on the applied pressure in the second working chamber of the compensation cylinder and/or depending on the dimension of the volume of the compensation cylinder, the damping properties of the vibration damper may additionally be easily influenced in this way.
According to an especially preferred embodiment of the present invention, the compensation cylinder is integrated in a damper fork. It is contemplated in this case that the damper fork is produced as a one-piece component, by which a later attachment and/or mounting of the compensation cylinder on the damper fork may be dispensed with. Production costs can thus be reduced by integrating the compensation cylinder in the damper fork.
The longitudinal central axis of the compensation cylinder is expediently inclined approximately 10 to 60° to the longitudinal central axis of the working cylinder. From this range of inclination, it is already clear that the configuration of the compensation cylinder on the front end of the working cylinder may be selected as a function of the available installation space and the available installation space may thus be used especially effectively.